How to do an alcohol wash

A wash by itself does not save a colony. It is worth being straight about that, because the number gets talked about as though writing it down were the intervention. It is not. What the wash does is make three other things possible, and none of the three work without it.

It lets you treat as needed instead of on a schedule. That means fewer treatments, not more — less chemical in the hive, less pressure toward resistance, and no wasted spring application on a colony that did not need one.

It lets you verify that a treatment worked. This is the one people skip. Without a number on both ends you cannot tell a successful treatment from a failed one, and a failed treatment feels exactly like a successful one until the colony is dead in February.

It lets you select for mite-resistant bees. The ability to breed for resistance resides entirely in the ability to measure. You cannot select for something you never measured.

The payoff is cumulative and it is deferred. Done consistently, this is the thing that saves colonies from winter death several years from now.

But the main use is one thing

Everything above is true, and none of it is why I do most of my washes. The main use is simpler than that: it is how I make absolutely sure I am going into fall with a low count.

That is the whole job. Not a low count in June, not an average across the season — a low count on the specific colonies that are about to make winter bees. Winter bees are reared from late summer through late autumn, and they are a physically different bee, built to live six months instead of six weeks. A mite feeding on that bee while it develops produces an adult that does not last the winter, whatever it looks like in October.

So a colony can be strong in September, heavy with stores, and still be finished. The bees in it are already compromised and there is nothing left to do about it. By the time that shows, the decision that caused it was made six weeks earlier.

The wash is how you refuse to find out in February. You get a number before you treat, you treat, you get another number to prove the treatment worked, and you go into fall knowing rather than hoping. Everything else the wash gives you is a bonus on top of that.

The skill the rest of mite management is built on.

What you need

• A Varroa EasyCheck. Just buy one. It is cheap and it is the right tool.
• 70% isopropyl alcohol. One fluid, always the same fluid.
• A half-cup dry measuring scoop. A level half cup of bees is roughly 300 bees. That is the sample size, every time.
• A rectangular plastic tub. Not for looking at anything — its job is to give you square corners so the bees pile up and you can get a clean scoopful.
• A pencil and something to write on. A number you did not write down is not a measurement.

The method

1. Find the queen first. Pull a frame of open brood from the middle of the nest, and look. If you cannot find her, check both faces of the frame you are about to shake. She is the one bee in there you cannot replace tomorrow.
2. Shake the frame of bees into the rectangular tub. One good sharp shake. This is also your second look for the queen — if she came off with them you will see her in the tub, and you have one more chance to catch it.
3. Shake the tub so the bees pile into one corner. Take your half-cup scoop out of that corner. Some bees will fly out while you do this and that is fine — the ones that leave are the older foragers, and the sample you want is the younger house bees that stay down in the tub. Those are the bees living on the brood, which is where the mites are.
4. Bees into the EasyCheck, alcohol over the top.
5. Gently shake and swirl for two full minutes. Two minutes is longer than it feels. Do not shake it hard — the motion you want is a swirl, and the duration does the work, not the violence. Whatever you settle on, do it the same way every time. A count is only worth anything next to your other counts, and changing the shake between them makes them incomparable.
6. Count with the light behind it. Hold the EasyCheck above eye level and look up at it from underneath. The mites are small roundish brown ovals and they read clearly against the light from below in a way they never do from above.
7. Write the number down, then go straight to the next hive on the same alcohol. Just remember how many mites are already sitting in the device, and subtract.

Do not scrape the scoop down the face of the frame. It is a common demonstration and I do not teach it, because in a new beekeeper's hands it is rough on bees and rough on the queen if she happens to be where you are scraping.

Reading the number

The sample is 300 bees, so divide your raw count by three to get mites per hundred. The threshold is 3 per 100. One number, one threshold. There are more sophisticated frameworks and you can go find them later; you will get further this season with one number you actually act on.

Raw count on 300 bees	Per 100	What to do
0 – 3 mites	Under 1	Nothing right now. Wash again in a few weeks.
4 – 8 mites	1 to under 3	Watch it. Plan a treatment, and know what you will use.
9+ mites	3 or over	Treat, and wash again afterward to confirm it worked.

Two things the number does not tell you

Up to 70 percent of the mites in a colony are sealed inside capped brood at any moment, where your sample cannot reach them. A low count in the middle of heavy brood rearing is good news, not a guarantee. This is also why the same count means something different in June than it does in October.

And the number is a snapshot of one colony on one day. Mite populations move, and they move fastest exactly when you stop looking.

About the bees you kill

Three hundred bees die every time you do this, and people hate it. It is worth sitting with rather than brushing off — but it is under one percent of a working colony, and a laying queen replaces them inside of a day. The alternative is not a colony where no bees die. The alternative is a colony where you find out in November.

A note on the video below

The demonstration linked at the foot of this page shows the general shape of the job well and is worth watching once. A few things in it are different from what I have written above, and I would rather point them out than let you find the contradiction on your own and not know which to follow.

He shakes hard for 60 seconds. I say gently swirl for two minutes. Here is the thing that actually matters, and it is bigger than either number: pick one method and do it the same way every time. The value of a mite count is almost entirely in comparing it to your other counts — this hive against that one, this colony before treatment against the same colony after. Change the shake between counts and you have thrown that away. You are no longer measuring mites, you are measuring how hard you happened to shake. Mine is two minutes, gently. Use his if you prefer. Just do not use both.

In the video he does not measure and does not use the strainer — he eyeballs a scoop of bees straight into the cup, because he is showing you the idea rather than running his own protocol on camera. Do not copy that part. Use the half-cup measure, every time, and use the strainer basket that comes with the EasyCheck. The half cup is what makes 300 bees mean 300 bees, and the strainer is what lets you lift the bees clear and actually see the mites. Without both, you have a jar of dead bees and a guess.

He gives the threshold as one per hundred, then says treat over two. I use three per hundred. Thresholds are genuinely contested and lower ones are defensible, particularly in an operation running hundreds of colonies where the cost of being wrong is spread thin. Pick one number and act on it. Mine is three.

None of that makes the video wrong. He runs a different operation than I do, in a different place, at a different scale, and his numbers come out of that. Which is the whole point of this site: when two beekeepers disagree, find out where each of them keeps bees before you decide who to follow.

When to do it

• Early August, before you decide on a treatment. This is the important one.
• After the treatment, to confirm it worked. This is the one everybody skips.
• Spring or early summer, if you can get one. It tells you what kind of season you are heading into.